Well surveying apparatus



DeC- 28, 1943- HENRI-GORGES DOLL 2,338,029

WELL sURvEYING APPARATUS Filed Jan. 21, 1941 2 sheets-Sheet 1 INVENTOR Henri Geofyes .Uoll

BY W FEMME/6, 'AkTSNEYs DeC- 28, 1943- Hr-:NR1-GEORGES DOLL 2,338,029

WELL SURVEYING APPARATUS Filed Jan. 2l, 1941 2 Sheets-Sheet 2 figg-4- 4 INVENTOR Henri Georyesa BY A @WML rfa-M hw jAWO N rammed uw. 2s, 1943 WELL SURVEYING APPARATUS Henri-Georges Doll, Houston, Tex., assigner to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Delaware Application January 21, 1941, Serial No. 375,197

(Cl. :i3-205.5)

8 Claims.

The present invention relates to bore hole surveying and more particularly to means adapted to be lowered into a bore hole on an electric cable for determining the inclination of the bore hole and the direction of the inclination at any desired point or points therein.

In my copending application Serial No. 370,466 filed December 17, 1940, for Well surveying instrument, there is disclosed apparatus for determining the inclination and direction of the inclination in bore holes, This is accomplished by lowering an instrument into the bore hole on a multi-conductor electric cable'which provides mechanical strength for raising and loweringthe apparatus in the bore hole and also enables complete control of the apparatus to be effected from the surface of the earth.

The present invention is addressed to somewhat analogous apparatus for making the same determinations when only a single electric conductor cable with or without a metallic sheath is employed.

Accordingly, it is an object of this invention to provide an apparatus for surveying bore holes in which only a single conductor cable is'utilized for controlling the apparatus-from the surface.

Another object of the invention is to provide a new and improved mono-conductor cable well surveying meansswh-,ich may be controlled from the surface of the earth without sacrificing any I of the speed, accuracy or other advantages of a. multi-conductor cable instrument.

The inventive idea involved is capable of being expressed in a number of different forms utilizing various electrical circuits. For purposes of illustration, however, a representative embodiment of the invention is described below in con- Y nection with the accompanying drawings in which:

Fig. 1 is a view in longitudinal section of well strip, cam operated switching means lactuated by the record strip, a compass, a member rolly ing on a surface of revolution, means for obtaining a photographic record of the positions of the compass and the rolling member and a'suitable electrical control circuit.

Thev principle of the invention can best beun'A derstood by referring to the non-limiting embodiment illustrated in the figures. Reierringfto Fig. 1, 'the well surveying apparatus comprises l a cylindrical casing lIII made of brass or other suitable material within which isv disposed a frame-work II on which the respective elements are mounted. The lower portion of the casing III is rounded at I2 and is provided with a circumferential shoulder I3 on which the framework II is adapted to be seated.

The upper end of the casing Ill is open and it is provided with a shouldered portion I4 adapted to seat a laterally extending flange I5 formed at the lower extremity of an externally threaded headpiece I6 by means of which the instrument may be attached to an electric cable or other apparatus (not shown). In order to provide a watertight joint, a gasket Il of rubber or other suitable material is placed over the iiange I5 and a ring I8 is screwed down tightly over it into the internally threaded upper portion of the casing I0. The ring I8 and the casing I8 are provided with suitable recesses I9 for receiving spanner wrenches to assemble and dis-assemble the unit.

The circuit for controlling the well surveying instrument, which will be described in detail hereinafter, includes a conductorl 2l) which passes through an insulated bushing 2| disposed y in a bore 22 formed in the headpiece I6. -The surveying apparatus constructed according to l the present invention;

Fig. 2 is a partial view in section taken along line 2-2 of Fig. 1, looking in the direction of the arrows and illustrating more clearly the film control mechanism and the film operated switching means;

Fig. 3 is a typical record made by the instru.

ment;

Fig. 4 is a schematic wiring diagram of the circuits employed in the apparatus shown in Figs. 1 and 2; and

Fig. 5 is a graphic representation of a complete cycle of operation of the apparatus shown in Figs. 1 and 2r.

The surveying instrument comprises essentially awater tight casing made of suitable non-magnetic material which is strong enough to withstand the pressures to which it is subjected, power means for driving a light sensitive record bushing 2| is retained in position by means of the screws 23 and 24 which are threaded on the conductor 20, as shown in the figure. `For thesake of clearness the electrical connections between the conductor 20 and the apparatus have not been shown in Figs. 1 and 2.

Attached to the framework Il is an electric motor 25, on the shaft of which is mounted a gear 26 which is adapted to drive a gear 2l secured to a crank arm 28 journalled in a bearing 29 in the framework II. The crank arm 28 is adapted tovbe snugly received within a U-shaped slot 30 (Fig. 2) formed at the upper extremity of an arm 3| which is pivotally mounted intermediate its ends at a point 32 on the framework I I. It will be apparent that when the motor 25 is energized to rotate the crank arm 28, the arm g will oscillate periodically about the pivot point At the lower end of the arm 3l is xed apawl 33 which is adapted to engage a ratchet wheel yielding engagement with the ratchet wheel 34 by means of a spring 36 which is secured to the arm 3-l. A second spring 31 is secured to a block 38 mounted on the framework Il which serves as a brake and permits the ratchet wheel 34 to turn in the direction of the arrow only.

Mounted in the framework Il beneath the sprocket wheel 34 is a conventional type film can 39 containing a roll of conventional type film. From the fllm can 39 is drawn a film strip 49 which passes over spaced apart horizontally disposed rollers 4I and 42 located adjacent the A boundary of an aperture 43 through which the inclination indicating means to be described below may be viewed. The end of the iilm` strip 40 is inserted within a longitudinally extending slot 42a (Fig. 1) formed in the shaft-35 on which the ratchet wheel 34 is mounted and a conventional type film can 44 is mounted over the shaft 35 "to receive the exposed film and protect it while the record is being removed.

The iilm strip 40 is provided with conventional perforations along at least one edge thereof which are adapted to be engaged by the teeth 45 on va sprocket wheel 46 rotatably'mo'unted on the framework -ll intermediate the film cans 44 and 39. Integrally formed with the sprocket wheel 46 are a pair of adjacent cams 41 and 48 (Fig. 4) which are adapted to cooperate with a pair of switches 49 and 59, respectively, which are also mounted on the framework Il.

'Ihe switch 49 (Fig. 4) is provided with a movable spring contact arm I which normally engages a spring contact 52. The contact arm 5l is adapted to be moved out of engagement with the contact 52 and into engagement with a contact 53 by thecam 41 acting through a spring arm 54 and a block of insulating material 55.

Pivotally mounted at the point 56. on the l' framework il and adjacent the spring arm 54 of the switch 49 is an arm 51, one end of which is continuously maintained in yielding engagement with the spring arm 54 by means of a weak tension spring 58. The other end of the arm 51 is provided with asmall button 59 made of any suitable magnetic material, near which is disposed a 'conventional type electromagnet 60.

The electromagnet 68 is so designed that it is not strong 'enough to attract the arm- 51 when the latter is in the position shown in Fig. 4. When the switch 49 has been actuated, however, and the button 59 is closely adjacent to the electromagnet 68, the latter is strong enough to hold the arm 51 and keep the switch 49 in the actuated position after the cam 41 has released the spring arm 54.

The switch 58- is provided with a spring arm 6| which is adapted to be actuated by the cam 48 to move an insulating member 62 secured to a pair of adjacent contact arms 63 and 64. In the normal position of the switch 50, the contact arm 64 is in engagement with the contact 65 and the contact arm 63 is out of engagement with the contact 66. Whenthe spring arm 6I is moved by the cam 48, the contact arm 64 is moved out of engagement with the contact 65 and the spring contact arm 63 is mved into engagement with the spring contact 66.

The lower portionof the aperture 43 is internally threaded (Fig. l) to receive an externally threaded tubular member 61. the interior wall ofv which is lthreaded to receive an externally threaded ring 68. Within the ring 68 are mounted a lens 69 and a diaphragm 10 having a small aperture 1I formed therein. By turningthe ring 68 either to the right or to the left as may be necessary, the lens 69 may be adjusted to focus the inclination indicating means which is described below on the portion of the film strip 49 disposed directly above the aperture 43.

Secured to the tubular member 61. is a radially extending flange 12 in which are mounted one or more electric lights 13 which provide the illumination necessary to light the inclination indicating means when the photographic record is being made. If the lamps 13 are series connected they should preferably be shunted by suitable resistances 14 which may also be mounted on the flange 12. The lower portion of the tubular f member 61 is formed with an outwardly extending conical portion 15 which is of such size and shape as to prevent any direct illumination from the lamps 13 from impingng upon the film strip 40 or the inclination indicating means disposed below.

The means for providing indications of the inclination of the bore hole comprises a curved member 16, made of glass or other suitable material, which is seated on an inwardly extending ring 11 formed within the framework Il and on which is disposed a freely rolling element 18, preferably a spherical steel ball. Mounted above the curved member 16 is a second curved member 19, also made of glass or other suitable material, which is spaced apart from the curved member 16 by a ring 80 made of brass, for example, such that the distance between the lower surface of the curved member 19 and the upper surface of the curved member 16 very slightly exceeds the diameter of the ball 18. The entire assembly is retained in position within the framework Il by means of a ring 8l, as shown in Fig. 1.

The lower surface of the curved member 19 and the upper surface of the curved member 16 are ground in the shape of segments of ellipsoids of evolution and the lower surface of curved 'member 16 is provided with etched circular rings 82 (Fig. 3) which, when viewed from the aperture 1| in the diaphragm 10, indicate the deviation of the axis of the casing l0 from the vertical for various positions of the ball 18. Whenever the axis of the casing I8 deviates from the vertical axis, the ball 18 rolls to the lowermost position on the curved member 16 and provides an accurate indication of such angular deviation.

The direction of the inclination of the' bore hole is afforded by means of a magneticcompass needle 83 which is pivotally mounted at the Ipoint 84 on "a member 85 located beneath and coaxially with the curved member 16. The member 85 is mounted on pivots 86 and 81 in a gimbal ring 88 which is pivotally mounted on an axis at right angles to the axis of the pivots 86 and 81. .A pendulum 89 is secured to the member 85 below the pivot 84 in such fashion that the l compass needle 83 is maintained in a horizontal plane at all times. To assist in differentiating between the north and south'ends of the compass needle 83, one end may be painted white and the other end black.

In Fig. 3 is shown a typical record of the inclination and the direction of the inclination made by the instrument. ball 18 with respect to the circular graduations 82 indicates accurately the angular deviationof the axis of the casing I0 from the vertical axis, and the position of the ball 18 with respect to the compass needle 83 indicates the direction of the inclination with respect to the magnetic north pole.

The position of the i Fig. 4 is a schematic wiring diagram of a circuit employed when a single conductor cable is used to raise and lower the instrument in a bore hole. The portion above the break represents the surface equipment while that below the break represents the circuit of the apparatus lowered into the bore hole. Referring to Fig. 4, theI circui't includes a source of voltage 90 which may be a direct current generator of about 110 volts, for example, one terminal of which is connected through a conductor 9| to ground, 92. In such case, the earth provides acurrent 'path to complete the circuit. If desired, the cable on which the apparatus is suspended in the bore hole may be provided with a metallic sheath which may be used as a ground instead of the earth. If a second conductor is available in the cable, it may also be used as a ground. An alternating current source, a converter, or a battery may be employed instead of the direct current generator 90, if desired.

The other terminal of the source of voltage 90 is connected through a conductor 93 -to one terminal of a variable resistance 94. The other end of the resistance 94 and the variable contact 95 thereof are connected together and through a conductor 96, an ammeter 91, a pilot light 96 and a switch 99 to the single conductor in the cable (not shown) on which the apparatus is suspended in a bore hole. The pilot llight 98 may be shunted by means of ar suitable fixed or variable resistance |0|. Y

'The lower end of the singleconductor |00 in the supporting cable is connected to the conductor 20 in the casing I0. The conductor 20 is connected toyone terminal of the winding 60a' on the electromagnet 60, the other terminal of which is connected by means of a conductor |02 to the contact arms 5| `yand 63 on the switches 49 and 50 respectively. The contact 52-on switch 49 is connected through a conductor |03 to the .contact 66 on the switch 50 and also to one terminal of the electric'motor 25, the other terminalof which is grounded to the casing |0 at the point |04. The contact 53 on the switch 49 is connected through a conductor |05 to the contact arm 64 on the switch 50 and the contact 65 of the switch 50 is connected through a con- .ductor |06 and through the lamps 13 to the ground point |04 on the casing |0.

In order to make a well survey with the apparatus described above, the framework is removed from the casing l0 before the appara-v tus is lowered into the bore hole and lm with perforations along one or both edges such as, for example 35 mm. motion picture film is placed in the film can 39. The lm can 39 is then placed in the framework and theleading end of the nlm strip 40 is pulled over the rollers 4| and 42, under the sprocket wheel 46 such that the teeth 45 enter the perforations thereof and into the receiving lm can 44 where it is inserted into the slot 44a formed in the shaft 35.

The shaft 35 is then given several turns to check the alignment of the fllm strip 40 and to ascertain if the mechanism is operating properly.

.The framework and all the parts attached thereto are then inserted in the outer casing I0, the necessaryV electrical connections are made, the headpiece |6'and the gasket |1 are placed into position and the ring I8 is tightly screwed down by means of a spanner wrench, providing a hermetical seal. An electrical cable (not shown) is then attached in any conventional manner to the externally threaded headpiece I6, electrical connections being made between the conductor 20 and the corresponding conductor |00 (Fig. 4) in the cable.

For the sake of accuracy, sinker with or without centering guides is rigidly attached above or below the well surveying instrument, but as this plays no part in the operation of the surveying instrument it is not shown in the drawings. The apparatus is then lowered to the desired depth in the bore hole Where it is brought to rest, or as is more customary, if possible, it is lowered belowthe desired depth and then pulled up slowly to the desired depth.

It will be assumed that at that instant the switch 99 is open and the positions of the cams 41 and 48 are as shown in Fig. 4. If it is now desired to obtain indications of the inclination of the well at that depth, the switch 99 is closed, completing a circuit from the ground 92 at the surface, the source of voltage 90, the conductor 93, the variable resistor 94, the conductor 96, ammeter 91, pilot light 98, switch 99, conductor |00 in the supporting cable, conductor 20, the winding 60a of the electromagnet 60, the contact arm 5| on switch 49 engaging contact 52, conductor |03, the motor 25, the ground |04 on the casing .|0, and through the liquid contained in the bore hole and the surrounding earth formations.

The motor 25 is `now energized and it proceeds to pull the lm strip 40 from the film can 39 over the rollers 4| and 42. The resistance of the circuit described above is so chosen that the motor 25 draws about 300 milliamperes and the. pilot light burns dimly, indicating that the film strip 40 is-being moved. The lights 13 are out.

The displacement of the film strip 40 rotates .the sprocket wheel 46, at the same time rotating the cams 41 and 48 in the directions indicated by the arrows. As shown in Fig. 4, the shapes and settings of the cams-41 and 48 is such that their sudden falls occur approximately simultaneously, but the recovery of the cam 48 precedes that of the cam 41 so that the contact arm 63 on the switch 50 engages the contact 66 before the contact arm 5| on the switch 49 disengages the contact 52.

After the period of time represented by the length A on Fig. 5 has elapsed, the cam 48 act ing through the spring arm 6| and the insulating member 62, will have moved the contact arm 64 on the switch 50 out of engagement with the contact 65 and the contact arm 63 into engagement with the contact 66. This completes a circuit from the conductor |02 through the contact arm 63 engaging contact 66 on the switch 50 to the ymotor 25, so that the latter remains energized regardless of what happens to the switch 49.

A short time B later (Fig. 5), the cam 41, acting through the spring arm 54 and the insulating member 55 on the switch 49, moves the contact arm 5| out of engagement with the contact 52 and into engagement with the contact 53. It will be noted that although the contact 52 is out of engagement with the contact arm 5|, the motor 25 remains energized because the contact arm 68 on the switch 50 is in engagement with the contact 66.

The movement of the spring arm 54 on the switch 49 is followed by the arm 51 which is turned about its `pivot 56 by the tension spring magnet 60 is so designed that it is strong enough in this position to retain the spring arm 54 and a long non-magnetic to the cable conductor,k for a suilicient length ofy of a casing adapted to be lowered into a bore hole. a single conductor cable extending from said casing to the surface of the. earth, a source of electrical energy at the surface of the earth having one terminal connected to ground and a second terminal connected to the conductor in said cable, first switching means at the surface for.

l time to give the record strip a `predetermined said recordstrip, the combination of a source of electrical energy at the surface of theearth, a l

when said first switching means is actuated to connect said source to said -cable conductor,- to give the record strip a predetermined displacement and for disconnecting said motor from the circuit after said displacement has taken place.

5. In apparatus for obtaining indications of the inclination of a bore hole, the combination of a casing adapted to be lowered into a bore hole, a single conductor cable extending from said casing to the surface cf the earth, a source of electrical energy at the surface of the earth havin-g one terminal connected to ground and a second terminal connected to the conductor in said cable, first switching means at. the surface for controlling the connection of said source to said cable conductor, a movable record strip in the casing, an electric motor for moving said record strip, said motor having one terminal grounded and a second terminal adapted to be connected to the conductor in said cable, electrical illuminating means in the casing, having one terminal grounded, and a second terminal adapted to be connected to said cable conductor, and switching means in said casing, actuated by the record strip after predetermined displacements thereof for connecting the motor to said cable conductor, when said first switching means is actuated to connect said source to said cable conductor, for a sufilcient length of time to give the record strip a predetermined displacement and for connecting the illuminating means to said cable conductor after said predetermined displacement has taken place. Y

6. In apparatus for obtainingindications of the inclination of a bore hole, the combination of a casing adapted to be lowered into a bore hole, a single conductor cable extending from said casing to the surface of the earth, a source of electrical energy at the surface of the earth, said source havingone terminal grounded and a second terminal connected to the conductor in said cable, rst switching means at the surface for controlling the connectiomof said source to said cable conductor, a movable record strip in the casing, an electric motor for moving said record strip, said motor having one terminal connected to ground and a second terminal adapted to be connected to said cable conductor, electric illuminating means in the casing having one terminal connected to groundA and a second terminal adapted to be connected to said cable conductor, and switching means in the casing and actuated by said record strip after predetermined displacements thereof for connecting the conductor in said cable to said motor, when said rst switching means is actuated to connect the source displacement and f/or connecting the 'conductor to said illuminating means afterthe predetermined Adisplacement has taken place.

7. In apparatus for obtaining indications of the inclination of a bore hole, which apparatus includes a casing adapted to be lowered into a b'ore hole, a movable record strip in the casing, an electric motor for moving the `record strip,

and electrical illuminating means for exposing circuit including a single conductor'cable for supplying electrical energy from said source to said motor and illuminating means, rst switching means at the surface for opening and closing said circuit, second switching means in the casing, normally connecting said circuit to -said motor, so that said motor is energized when said first switching means is actuated to close said circuit, cam means driven by said record `strip for actuating said second switching kmeans to make a second connection between said circuit and said motor and to prepare a connection be-v,

tween said illuminating means and said circuit, and for releasing said switching means after the motor has given said record strip a predetermined displacement, and electrical means connected in circuit with saidvconductor for holding in part of said switching means after the same has been released by said cam means so as to complete the connection between said illuminating'means and circuit and to break the connection between said motor and said circuit.

8. In apparatus for obtaining indications of the inclination of .a bore hole, which apparatus includes a casing adapted to be lowered-intoa bore hole, a movable record strip in the casing, an electric motor for moving the record strip, and electrical illuminating means for exposing said Vrecord strip, the combination of a source of electrical energy at the surface of the earth, a circuit including a single conductor cable for supplying electrical energy from said source :to said motor and illuminating means, first switching means at the surface for opening and closing said circuit, indicating means connected to said conductor at the surface, second switching means inthe casing, normally,` connecting said circuit to said.

motor, so that said motor is energized when said first switching means is actuated to close said"a circuit, campmeans driven by said recordstrip for actuatingv said second switching vmeans to make a second connection between said circuit and said motor and to prepare a connection between said illuminating means and said circuit, and for releasing said switching means after the motor has given said record strip a predetermined displacement, and electrical means connected incircuit with said conductor for holding in part of said switching means after the same has been released by said cam means so as to complete the connection between saidilluminating means and circuit and to break the connection between salti motor and said circuit, the electrical characteristics of the circuit including the indicating means being diierent for each said connection of said circuit, whereby said indicating means will provide a different indication at the surface for each said connection.

HENRI-GEORGES DOLL. 

